The present invention relates to a charging device and a system for charging a motor vehicle, which charging device and system are suitable for supplying electrical current and gas to the motor vehicle for the operation of a solid-gas battery.
Motor vehicles with electric motors are an alternative to motor vehicles with conventional drive by way of internal combustion engines. An advantage of electric motors is the local absence of emissions with regard to pollutant emissions. The drive energy of an electric motor is generally provided by way of rechargeable accumulators. In this context, as accumulators, use is often made of lithium-ion batteries which impart the required drive energy for the operation of the motor vehicle.
Alternatives to lithium-ion batteries are, for example, lithium-air batteries or, more generally, solid-gas batteries, which have for example a considerably greater energy density and power capacity than present lithium-ion batteries, which can have an advantageous effect inter alia on a possible range of the motor vehicle. As a result, for motor vehicles with solid-gas batteries, special charging devices are also required, which provide the motor vehicle with the required fuel for the operation of the solid-gas battery.
The document US 2012/0041628 A1 describes a system and a method suitable for electrically charging a metal-air battery arranged in a motor vehicle. For this purpose, there are also arranged in the motor vehicle a compressor and a tank which, together with an external power source, permit a charging cycle of the metal-air battery.
An object on which the invention is based is that of providing a charging device and a system which are suitable for permitting a supply of electrical current and gas for a solid-gas battery of a motor vehicle in a simple manner.
The object is achieved by way of a charging device and system in accordance with embodiments of the invention.
According to a first aspect of the invention, a charging device for charging a motor vehicle includes an energy supply unit which is arranged externally with respect to the motor vehicle and which is designed to provide electrical current for a solid-gas battery of the motor vehicle. The charging device furthermore includes a gas supply unit which is arranged externally with respect to the motor vehicle and which is designed to provide gas for the solid-gas battery of the motor vehicle. Furthermore, the charging device has at least one supply connection by way of which the energy supply unit can be coupled to the motor vehicle, during the course of a charging process, for the supply of electrical current for the solid-gas battery and by way of which the gas supply unit can be coupled to the motor vehicle, during the course of a charging process, for the supply of gas for the solid-gas battery.
By way of a charging device of said type, charging with electrical current and gas for a motor vehicle which has a solid-gas battery is made possible in a simple manner.
Solid-gas batteries have an anode, which is composed of a solid, and a cathode, which is spaced apart from said anode and which is composed for example of mesoporous carbon and which may figuratively be viewed as a type of sponge. Between the solid anode and the cathode, there is typically situated an electrolyte which, depending on the embodiment of the solid-gas battery, may for example be in solid or liquid form. By way of a supply of gas, a current flow is induced in the solid-gas battery, which current flow can be utilized for the purposes of supplying energy. It is basically the case, during discharging of the solid-gas battery, that positive ions and electrodes are detached from the solid anode and pass over into the electrolyte. During the further process, the positive ions become coupled, at the cathode, to atoms or molecules of the supplied gas and are electrochemically bonded there. The electrons that are emitted during said process are available for charge transport, and thereby permit a current flow and an electrical supply to components coupled to the solid-gas battery. If, for example, an external voltage potential is applied to the solid-gas battery, which voltage potential exceeds the potential during the discharging of the solid-gas battery, the described process is reversed, and the solid-gas battery is charged. In this case, the electrochemical bonds between the ions of the solid anode and the atoms or molecules of the supplied gas are severed again. As a result, the ions travel through the electrolyte to the solid anode and set down on the latter by way of recombination with electrons. Furthermore, the electrochemically bonded gas is also emitted again, which gas is for example released into an exterior region or can be recirculated for a further cycle of the solid-gas battery.
With regard to the claimed invention, by way of the described charging device, it is the case inter alia that an electrical current is provided by the at least one supply connection, which electrical current represents an external voltage potential and thus permits charging of the solid-gas battery. The energy supply unit is for example a separate component of the charging device, which includes for example a generator, and/or said energy supply unit is coupled to an energy supply network from which it draws the electrical current required for the charging of the motor vehicle. It is preferable for direct current or direct-current voltage to be provided by the energy supply unit, because this permits a faster charging process than charging with alternating current or alternating-current voltage. Charging with alternating current or alternating-current voltage is however likewise possible, such that, in this context, it is for example the case that the charging device or the motor vehicle includes components for current or voltage conversion, such as for example a rectifier. In this way, it is ensured that the solid-gas battery is supplied with direct current or direct-current voltage which is required for the charging of the solid-gas battery.
The gas that is emitted during the course of the charging process may for example be released from the solid-gas battery or from the motor vehicle, or said gas is reused for a further driving cycle of the solid-gas battery. In this case, it is for example the case that a high-pressure tank is arranged in the motor vehicle, which high-pressure tank can be coupled to the at least one supply connection of the charging device.
If the emitted gas is for example released from the motor vehicle, it is also the case that gas for the solid-gas battery is provided by way of the described charging device, which gas can be supplied to the motor vehicle during the course of the charging process. A reason for this may be that a user of the motor vehicle seeks to exchange the previously used gas for a different gas type in order to thereby for example increase the efficiency of the solid-gas battery and the possible range of the motor vehicle. In this context, the charging device and the motor vehicle are correspondingly designed to perform such a gas exchange during the course of the charging process. Furthermore, in such a case, the solid-gas battery is designed to be operated using different gas types. For example, the gas supply unit of the charging device then includes multiple gas tanks with different gas types for solid-gas batteries, and provides said different gas types for the charging process of the motor vehicle. Alternatively or in addition, the gas supply unit is also coupled to a gas supply network, and draws one or more gas types therefrom for supply to the motor vehicle.
The charging with electrical current and gas for the solid-gas battery may for example take place simultaneously or in temporal succession during the course of the charging process. The at least one supply connection is in this case designed correspondingly for this purpose, and is coupled to the energy supply unit and to the gas supply unit. For example, the at least one supply connection includes an insulated electrical line for the supply of the electrical current during the course of the charging process, which insulated electrical line is surrounded by a gas line for the supply of the gas. During the course of the charging process, it is for example also possible for gas to be received from the motor vehicle via said gas line, which gas is for example emitted during the charging of the solid-gas battery. Alternatively, the charging device also includes, for this purpose, a further gas line which is for example also couplable to the motor vehicle by way of the at least one supply connection. The at least one supply connection is, in this context, realized for example as a type of combination connection, which is thus designed so as to permit at least the described functions.
Alternatively or in addition, the described charging device has further supply connections such that, during the course of the charging process, it is for example the case that a first supply connection is available for the supply of electrical current and a second supply connection is available for the supply of gas for the solid-gas battery. Here, the second supply connection may also be designed for receiving gas from the motor vehicle, or it is for example the case that a third supply connection is provided which performs said function. The one or more supply connections are, in this context, designed so as to have for example common connector shapes in accordance with their function. They may however also be designed differently in terms of their shape such that, during the course of the charging process, it is at least the case that charging with electrical current and/or gas for the solid-gas battery is possible at all times.
In a refinement of the first aspect, the gas supply unit includes a compressor which is designed to compress gas for the solid-gas battery and supply said gas to the motor vehicle, said gas being provided during the course of the charging process.
In this way, it is possible for the gas required for the operation of the solid-gas battery to be provided to the motor vehicle in compressed form, in order to thereby for example fill a high-pressure tank of the motor vehicle. By virtue of the gas being supplied to the motor vehicle in compressed form during the course of the charging process, it is possible for a greater gas volume to be stored, for example in the high-pressure tank of the motor vehicle, which can have an advantageous effect on the power capacity of the solid-gas battery and the possible range of the motor vehicle. Correspondingly, it is also possible for the dimensioning of the high-pressure tank in the motor vehicle to be adapted, which may be performed inter alia in a manner dependent on the gas pressure, the desired possible range of the motor vehicle and the power capacity of the solid-gas battery.
The compressor is, as a component of the gas supply unit, arranged externally with respect to the motor vehicle and, in accordance with the claimed invention, is for example integrated into an external charging station. This permits for example storage of compressed gas in the high-pressure tank of motor vehicles which themselves do not have an on-board compressor. In this way, it is possible to realize motor vehicles with solid-gas batteries in which weight, volume and costs that would be involved in the case of a compressor being installed in a motor vehicle can be eliminated. The weight reduction of the motor vehicle made possible by way of the described charging device has an advantageous effect on the energy density and power capacity of the solid-gas battery, and, by way of the associated volume reduction, permits an adaptation of other components of the motor vehicle, such as for example of the high-pressure tank. On this basis, said high-pressure tank can be made larger in terms of its dimensions than would be possible in the case of a motor vehicle with compressor. Consequently, the arrangement of the compressor in the charging device externally with respect to the motor vehicle contributes to more efficient operation of the solid-gas battery.
In a further refinement of the first aspect, the charging device includes a gas-receiving unit which is arranged externally with respect to the motor vehicle and which is designed to receive gas from the motor vehicle during the course of the charging process.
In this way, it is possible by way of the gas-receiving unit for gas to be received from the motor vehicle, and stored for example in a gas tank, during the course of the charging process. For example, an exchange of the gas for the solid-gas battery is made possible in this way. If the solid-gas battery is for example designed to be operated with synthetic air or pure oxygen, the gas types can be released and exchanged as required during the course of the charging process. For example, here, the gas supply unit of the charging device includes the provision of at least the two stated gas types, and thus permits the charging with the desired gas during the course of the charging process. It is thus possible, for example, for synthetic air which has previously been introduced into the tank to be exchanged for pure oxygen, which possibly permits greater efficiency of the solid-gas battery, and thus a greater range of the motor vehicle, in relation to the synthetic air.
Furthermore, by way of the gas-receiving unit, it is also possible during the course of the charging process for the emitted gas, which as a result of the operation during the discharging of the solid-gas battery was chemically bonded to the positive ions of the solid on the cathode, to be received and supplied again to the high-pressure tank of the motor vehicle.
In a further refinement of the first aspect, the gas-receiving unit is coupled to the gas supply unit and is designed to at least partially supply to the gas supply unit the gas that is received from the motor vehicle during the course of the charging process.
In this context, it is for example the case that the gas that is emitted during the course of the charging process is received from the motor vehicle by way of the at least one supply connection and, during the further process, is supplied to the gas supply unit for example via one or more feed lines. The received gas can thereupon be compressed again by way of the compressor and conducted, for a further driving cycle, to the high-pressure tank of the motor vehicle for the solid-gas battery. The received gas is possibly supplied only partially to the gas supply unit and to the motor vehicle, for example because the quality of the received gas does not altogether correspond to the desired specifications. As a result, it is for example the case that a part of the received gas is mixed with gas which is provided via the gas supply unit by a gas supply network or by a gas tank, such that the gas supplied to the motor vehicle for the solid-gas battery meets the predefined requirements. The monitoring of the quality of the received and supplied gas is performed for example by way of sensors in the one or more feed lines, which sensors analyze for example a concentration of various substances which are detrimental to the operation of the solid-gas battery.
Furthermore, the gas-receiving unit may for example also be in the form of a simple feed line which couples the at least one supply connection of the charging device to the compressor. Particularly straightforward recycling of the emitted gas of the solid-gas battery of the motor vehicle is realized in this way during the course of the charging process.
In a further refinement of the first aspect, the gas supply unit includes a gas treatment unit.
The gas treatment unit permits for example filtering of the gas before said gas is supplied to the motor vehicle for the solid-gas battery. In this way, it is possible for constituents that can adversely affect operation of the solid-gas battery to be filtered out of the gas. The gas treated in this way is then supplied for example to the high-pressure tank of the motor vehicle.
For example, the gas can, by way of the gas treatment unit, be substantially purified for removal of water and carbon dioxides, which adversely influence the operation of the solid-gas battery even in the range from, for example, 100 to 400 ppm, and which can permanently damage the solid-gas battery. Other contaminants, such as for example particles and hydrocarbons, may also be separated out in this way, such that, for example, as a result of treatment of the gas, synthetic air is generated which is composed substantially only of nitrogen and oxygen. The synthetic air may thereupon be supplied to the motor vehicle during the course of the charging process, and is stored for example in the gas-receiving unit of the charging device.
The gas treatment unit is in this case for example coupled to one or more gas tanks of the gas supply unit and to the gas supply network and thus permits purification of the gas before said gas is supplied to the motor vehicle during the course of the charging process.
This is conducive to achieving a longer service life of the solid-gas battery, and it is possibly also the case that a time for maintenance of the solid-gas battery of the motor vehicle is delayed.
In a further refinement of the first aspect, the charging device includes at least one gas tank which is arranged externally with respect to the motor vehicle and which is coupled to the gas supply unit.
As already described, the gas supply unit may be coupled to at least one gas supply network and/or to at least one gas tank in order, during the course of the charging process, to permit charging with gas for the solid-gas battery of the motor vehicle. The at least one gas tank includes for example synthetic air or pure oxygen.
In a further refinement of the first aspect, the charging device includes an air-conditioning system which is designed to cool or heat the gas for the solid-gas battery of the motor vehicle before and/or during the charging process.
By way of the air-conditioning system of the described charging device, it is possible for the gas to be temperature-controlled to an optimum temperature which permits for example fast and/or battery-preserving charging with the gas in conjunction with the charging process of the motor vehicle. For example, by way of the air-conditioning system, a certain temperature range of the gas provided by the gas supply unit is maintained, which temperature range realizes optimum operation of the solid-gas battery of the motor vehicle within a short time. For example, the at least one gas tank is a cryogenic store which permits for example charging with liquid oxygen for the motor vehicle. During operation of the motor vehicle, it is for example the case that the liquid oxygen is supplied from the high-pressure tank to the solid-gas battery and evaporates owing to ambient temperatures, and is thus present in the gaseous state of aggregation again.
In a further refinement of the first aspect, the charging device includes a communication interface which is designed to, during the course of the charging process, exchange signals for the control of the charging process between the charging device and the motor vehicle.
By way of the communication interface, it is possible for the charging device to communicate with the motor vehicle and thus control the charging process of the motor vehicle. In this context, the motor vehicle is, for example, equipped with a corresponding communication interface which permits such communication. For example, in this way, a vehicle or battery management system of the motor vehicle is controlled by the charging device, which vehicle or battery management system monitors inter alia the charging process. Here, the communication includes a transmission of various items of information, such as for example a status of the charging process, a system pressure, an oxygen content of the supplied gas, a fill level of the high-pressure tank, a pressure in the solid-gas battery, a gas temperature, a battery temperature. The charging device is furthermore designed to determine the items of information and measurement values required for the communication, and can for example monitor the charging process by way of various sensors. This, for example, also encompasses control of a thermal management system.
Owing to the communication between the charging device and the motor vehicle, an optimum and reliable charging process for the solid-gas battery is made possible.
According to a second aspect, a system for charging a motor vehicle includes a charging device according to one of the above-described refinements of the first aspect and the motor vehicle, which has a solid-gas battery and at least one charging connection for the supply of electrical current and/or gas for the solid-gas battery during the course of a charging process by way of the charging device.
The charging device represents, for example, a charging station in the public infrastructure for motor vehicles with solid-gas batteries, and may be understood substantially analogously to a refueling station for example for motor vehicles with internal combustion engines. By contrast to known refueling stations, a charging station of said type permits charging with electrical current and/or gas for solid-gas batteries for motor vehicles. In this way, it is possible to realize operation of motor vehicles with electric motors which exhibit considerably greater potential, with regard to the possible energy density and power capacity, then previous motor vehicles with, for example, lithium-ion accumulators.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.